4-β-[(tetrahydropyran-2-yl)methoxycarbonyl]amino-4'-tert-butyldimethylsilyloxy-4'-O-demethyl-4-desoxypodophyllotoxin                                                                                                                                                              在
                                                                                                                                                                                 Dowex 50 20-200 ion-exchange resin                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲醇                                                                                  为溶剂,
                                                                                                                                                    反应 16.0h,
                                                                                                                以55%的产率得到[(5S,5aS,8aR,9R)-9-(4-Hydroxy-3,5-dimethoxy-phenyl)-8-oxo-5,5a,6,8,8a,9-hexahydro-furo[3',4':6,7]naphtho[2,3-d][1,3]dioxol-5-yl]-carbamic acid tetrahydro-pyran-2-ylmethyl ester